Dave Smith Instruments Announces Sequential Prophet X Synthesizer

'Samples through analog filters' seems to be the order of the day, but there's more to it than that.

Published May 1, 2018 by John G.

'Musicians have been asking for samples through real analog filters for a long time,' says Dave Smith, and as we take a look at the newly-announced Sequential Prophet X it's worth discussing first and foremost how it fulfills that request.

Smith and Sequential have experience with 'samples through real analog filters' going all the way back to the mid to late 80s, with the original Sequential Circuits releasing a series of sample-based products in its twilight years including Prophet 2000/2002/3000 synths and the Studio 440 groovebox, all of which are still revered for their 'characterful' sound in spite of their era-appropriate paucity of sample memory.

Some of the character ascribed to these synths may be due to their 12-bit sampling engines (16-bit on the Prophet 3000) and analog VCAs, but much of it is likely due to their analog filters, which were resonant on the 2000, 2002 and 3000. Browsing comment threads about these classics reveals an abundance of 'I'll never part with it' sentiments with many specifically praising the analog filters.

While the vintage Prophet samplers under discussion used Sequential-/DSI-standard Curtis IC filters, for Prophet X Smith and co. have made an interesting choice with the Sound Semiconductor 'Fatkeys' SSI-2044 resonant low pass filter. While DSI's other recent forays outside of Curtis designs have been the discrete designs found on Pro 2, Sequential Prophet 6 and OB-6, SSI-2044 is an IC and is a newly-available update of Dave Rossum's revered Solid State Micro SSM2044 design with improvements by the original designer.

SSM2044 can be found in an impressive list of vintage synths and samplers, from well-known classics like E-mu SP-12, SP 1200 and Emulator-I, Korg Mono/Poly, Polysix and Trident, PPG Wave 2.2/2.3 and even Simmons Drums SDS5 to more obscure entries like Octave Plateau Voyetra Eight, Crumar Bit 01 and Bit 99, Kawai K3 and Siel Opera 6 and Kiwi.

SSI-2044 just became available last year, likely around when initial designs for Sequential Prophet X were being drawn up, and thus to our knowledge hasn't been used in any other mass-produced modern instruments, but given its progenitor's legacy it seems likely that Prophet X will have no shortage of the coveted, filter-derived character found in the vintage SCI samplers as well as the products that used SSM2044.

For factory-installed sample content as well as optional add-on packs, DSI has partnered with 8Dio, purveyors of highly-regarded sample libraries used by an impressive list of well-known artists and composers and in an equally impressive list of movies, shows and games. 8Dio describes itself as the inventor of 'deep-sampling,' though it's a little hard to get a handle on whether that's strictly a marketing term or refers to a specific technical specification or process.

Either way, Sequential Prophet X seems to have been designed from the ground up with support for 'deep-sampling,' with two multi-sampled stereo instruments per voice, and needless to say it won't suffer from its forebears' limitations on sample memory or sample storage. Prophet X comes with 150GB of 16-bit 48kHz samples from 8Dio with an additional 50GB of user memory that can be filled by purchasing additional libraries. Support for loading of user samples is planned for later this year.

It's worth pointing out, too, that while 'samples through analog filters' seems to have been the primary design consideration the story certainly doesn't end there, with two digital oscillators per voice seemingly derived from those in Prophet 12 that offer a variety of waveshapes as well as waveshape modulation. There's also a full-featured arpeggiator, a polyphonic step sequencer and a digital effects section that similar to the ones in Sequential Prophet 6, OB-6 and Prophet Rev2 that offers stereo and BBD-style delays, spring and plate reverbs, chorus, flanger, phaser, rotating speaker and distortion as well as a digital high pass filter, handy for further sculpting sampled sounds.

Sequential Prophet X is bi-timbral with a dedicated 'Output B' stereo output in case you want to record and/or process its two parts separately. There are four envelope generators – one for filter, one for VCA and two assignable utility envelopes – and a beefy modulation matrix with 16 slots, 28 sources and 88 destinations on top of 11 fixed sources like pressure, velocity, footswitch, LFOs, envelopes and mod wheel. Speaking of the mod wheel, Prophet X has no shortage of performance controls: in addition to pitch and mod wheels there are Tempest-style pressure-sensitive touch strips as well as a pair of 1/4" inputs that can work with expression pedals or 0-5V control voltages. There are also two footswitch inputs for sustain and sequencer playback.

Prophet X boasts a 5-octave, semi-weighted keybed with velocity and channel after touch topped by a lavish top panel replete with 56 knobs, 50 buttons and 3 OLED displays. In addition to its MIDI in/out/thru ports and USB to host port for MIDI-over-USB there's also a MIDI to device port specifically for sample import.

By focusing on its strengths, i.e., the sound engine and signal path, and leaving sample recording/preparation and deep automation to other devices and existing workflows, Dave Smith has created an amazing modern instrument with a broad sonic palette that will appeal to a wide variety of users, from gigging keyboards to studio hobbyists to score/soundtrack composers.

As Smith himself puts it, 'composers will love the Prophet X for soundtracks and synth geeks will love it for its sound mangling potential. But it's really for everyone because it covers such a wide range of sounds.' 8Dio co-founder Tawnia Knox adds 'The Prophet X has almost infinite possibilities. But more importantly, it has a soul. It's alive. You can touch your sounds in a different way than you ever could.'